BOCA RATON, Florida — Donald Trump blamed Sen. Bernard Sanders‘ supporters Sunday for inciting protests at his rallies, and vowed to send his own supporters to Sanders‘ events, as the GOP front-runner continued to court controversy ahead of Tuesday’s slate of primaries.

Liberal pressure groups continued to cheer on the protests, saying Mr. Trump had gone outside the bounds of acceptable political discussion, but Mr. Trump’s backers called the attempts to shut down his rallies an affront to free speech.

“Bernie Sanders is lying when he says his disruptors aren’t told to go to my events,” Mr. Trump tweeted. “Be careful Bernie, or my supporters will go to yours!”

The issue came to a head Friday as Mr. Trump canceled a rally in Chicago after protesters showed in strength to protest. It was the latest instance in what’s become a running series of high-profile disruptions at Mr. Trump’s massive rallies.

On Saturday a man tried to rush the stage and grab Mr. Trump in Dayton, Ohio, but was blocked by Secret Service agents who have been assigned to protect Mr. Trump, his campaign said.

His speech was repeatedly interrupted by other protesters.

“I hope they arrest these people, because, honestly, they should be,” Mr. Trump said. “The only way to stop the craziness is to press charges.”

Protesters were preparing for another round Sunday night at a Trump rally in Boca Raton, coming through the gates with homemade signs reading “Stop the hate.”

Kate Newton, one of the protesters, said she came in peace and was asked to leave the rally once she showed her sign.

“Trump came here to spread vitriolic, xenophobic hate, and I have my First Amendment right to come here and protest it,” said Ms. Newton, a supporter of Mr. Sanders.

David Ravanesi, a Trump volunteer at the event, said Ms. Newton was only asked to take down her sign and was not asked to leave the event. Ms. Newton decided to leave on her own.

Mr. Ravanesi said all homemade signs were being taken, and only signs issued by the Trump organization were to be allowed.

Indeed, signs reading “Trump Lives Matter” and “Build that Wall” were both confiscated earlier in the night.

The Boca Raton event had a so-called special section for protesters outside of the event’s gates, and before the rally started, a man on a loudspeaker told protesters to leave, as this was a private event paid for and rented out by Mr. Trump. An announcement was also made to attendees not to touch any protesters that may appear during the event but to point them out to security.

“There are minor disturbances and then the media blows it up,” Tom Duke, 51, from Del Ray Beach, said of the protesters. “This crowd is just here to hear Trump.”

Kevin Rebal, 46, said many protesters were denied entry to the event while he was walking in, and it was good riddance.

“There’s signs saying Trump’s a member of the KKK — all Bernie supporters — and the police got rid of them,” Mr. Rebal said. “This is a Trump rally, and they want to come here and cause discord, to provoke. We have First Amendment rights too.”

On Saturday Mr. Trump blamed Mr. Sanders‘ supporters for disrupting his Friday night rally in Chicago, which Mr. Trump had to cancel, the tycoon said, after consultation with law enforcement.

“Some represented Bernie, our communist friend,” Mr. Trump said of the Chicago protesters at an event in Dayton, Ohio, on Saturday. Later in the day, at a rally in Cleveland, Mr. Trump speculated where the protesters came from: “You know where they come from? Bernie’s crowd. They’re Bernie’s crowd,” Mr. Trump said.

Mr. Sanders fought back on Saturday, calling Mr. Trump a “pathological liar,” a line he repeated Sunday night at a CNN town hall meeting. He said Mr. Trump must denounce violence at his rallies.

However, the Chicago protests against Mr. Trump were organized in part by MoveOn.org, a progressive group that has endorsed Mr. Sanders for president and is backed by billionaire George Soros.

On Saturday the group sent an email fundraising off the protests and warning disruptions would continue for as long as Mr. Trump continued to run and make speeches that MoveOn called “bullying, hate-baiting, and incitements to violence.”

But Mr. Sanders minimized the connection and said his supporters were not to blame, but only responding to Mr. Trump.

“I don’t think our supporters are inciting. What our supporters are doing is responding to a candidate who has, in fact, in many ways, encouraged violence,” Mr. Sanders said at a Saturday news conference in Chicago. “When he talks about ‘I wish we were in the old days when you could punch somebody in the head,’ what do you think that says to his supporters?”

At Sunday’s town hall meeting, Mr. Sanders also downplayed his own association with his supporters, saying he can’t be held responsible for everything any one of his “millions” of voters might do.

Earlier on Sunday Mr. Sanders opened his remarks at a rally at Ohio State University in Columbus by panning the news that Mr. Trump might pick up the legal bills for “folks that go around beating up people.”

“A candidate for president of the United States should condemn [violence], not encourage violence,” Mr. Sanders said, sparking applause from the feverish crowd that came out to see him. “You don’t go around saying, ‘It is OK to beat somebody up and I will pay the legal fees.’ That is not what this country is about.”

Mr. Trump hasn’t backed down in defending his supporters. In a series of interviews on Saturday, Mr. Trump said the people who attend his rallies are “taunted” and “harassed” by protesters.

“They want me to tell my people please be nice, be nice,” Mr. Trump said on Saturday. “My people are nice.”

Mr. Trump said he was going to “start pressing charges” against the protesters who continually interrupt his events.

Sally Scott, of Willoughby, Ohio, 58, blamed the protesters, not Mr. Trump, for the violence in Chicago, and said it makes her more motivated to support the New York billionaire.

“This is really the time we have to show up, because we have to let the protesters know that we won’t be afraid, we won’t be scared away,” Ms. Scott said. “This is our First Amendment right, so I think it is even more important to show up.”

Mr. Trump’s fellow GOP candidates, however, are increasingly blaming him for inciting the protests.

“This is a man who in rallies has told his supporters to basically beat up the people who are in the crowd and he will pay their legal fees,” Sen. Marco Rubio said over the weekend. “Someone who has basically encouraged people in the audience to rough up anyone who stands up and says something he doesn’t like.”